Three Young Texans

Three Young Texans is a 1954 Western film starring Jeffrey Hunter and Mitzi Gaynor.

Johnnys nervous because his father Jim is also a gambler. Jim goes to Mexico, gets drunk, catches a man named McAdoo cheating at cards, then shoots him in selfdefense. McAdoos two associates, Catur and Joe, decide to blackmail Jim into helping them rob a train of its 50,000 in payroll loot. If he refuses, theyll tell the law Jim shot their friend in cold blood.To help his father, Johnny robs the train first. He hides the money with the 700. A posse is formed, which Johnny joins to go search for a thief who is actually himself. ........

Source: Wikipedia